United States Department of Agriculture The Ecology and Management of Moist Mixed-Conifer Forests in Eastern Oregon and Washington: a Synthesis of the Relevant Biophysical Science and Implications for Future Land Management Peter Stine, Paul Hessburg, Thomas Spies, Marc Kramer, Christopher J. Fettig, Andrew Hansen, John Lehmkuhl, Kevin O’Hara, Karl Polivka, Peter Singleton, Susan Charnley, Andrew Merschel, and Rachel White Forest Pacific Northwest General Technical Report September Service Research Station PNW-GTR-897 2014 The Forest Service of the U.S. Department of Agriculture is dedicated to the principle of multiple use management of the Nation’s forest resources for sustained yields of wood, water, forage, wildlife, and recreation. Through forestry research, cooperation with the States and private forest owners, and management of the National Forests and National Grasslands, it strives—as directed by Congress—to provide increasingly greater service to a growing Nation. 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Authors Peter Stine is a biogeographer and Christopher Fettig is a research entomologist, U.S. Department of Agriculture, Forest Service, Pacific Southwest Research Station, 1731 Research Park Drive, Davis, CA 95618; Paul Hessburg is a research ecologist, John Lehmkuhl is an emeritus scientist, Karl Polivka is a research fish biologist, and Peter Singleton is an ecologist, U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station, Forestry Sciences Laboratory, 1133 N. Western Ave., Wenatchee, WA 98801; Thomas Spies is a research forester, U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station, Forestry Sciences Laboratory, 3200 SW Jefferson Way, Corvallis, OR 97331; Susan Charnley is a research social scientist, and Rachel White is a science writer/editor, U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station, Forestry Sciences Laboratory, 620 SW Main St., Suite 400, Portland, OR 97205; Marc Kramer is an associate professor, University of Florida, 3165A McCarty Hall, Gainesville, FL 32611; Andrew Hansen is a professor, Montana State University, Landscape Biodiversity Lab, 310 Lewis Hall, Bozeman, MT 59717; Kevin O’Hara is a professor, University of California–Berkeley, Department of Environmental Science, Policy, and Management, 130 Mulford Hall #3114, Berkeley, CA 94720; and Andrew Merschel is faculty research assistant, Department of Forest Ecosystems and Society, Oregon State University, 321 Richardson Hall, Corvallis, OR 97331. Cover photographs: (upper left and lower right) Okanogan-Wenatchee National Forest, Washington, by John Marshall; (lower left) Columbia River Gorge, Oregon, by Miles Hemstrom; (upper right) Deschutes National Forest, Oregon, by Tom Spies. Abstract Stine, Peter; Hessburg, Paul; Spies, Thomas; Kramer, Marc; Fettig, Christo- pher J.; Hansen, Andrew; Lehmkuhl, John; O’Hara, Kevin; Polivka, Karl; Singleton, Peter; Charnley, Susan; Merschel, Andrew; White, Rachel. 2014. The ecology and management of moist mixed-conifer forests in eastern Oregon and Washington: a synthesis of the relevant biophysical science and implications for future land management. Gen. Tech. Rep. PNW-GTR-897. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 254 p. Land managers in the Pacific Northwest have reported a need for updated scientific information on the ecology and management of mixed-conifer forests east of the Cascade Range in Oregon and Washington. Of particular concern are the moist mixed-conifer forests, which have become drought-stressed and vulnerable to high-severity fire after decades of human disturbances and climate warming. This synthesis responds to this need. We present a compilation of existing research across multiple natural resource issues, including disturbance regimes, the legacy effects of past management actions, wildlife habitat, watershed health, restoration concepts from a landscape perspective, and social and policy concerns. We provide considerations for management, while also emphasizing the importance of local knowledge when applying this information at the local and regional level. Keywords: Disturbance ecology, landscape restoration, land management, resilience, stewardship. Executive Summary Millions of hectares of Western forests have been negatively affected by drought and by insect and disease outbreaks, and are overloaded with fuel, priming them for unusually severe and extensive wildfires. In light of these trends, public support for One priority of the forest restoration has grown. One priority of the USDA Forest Service is to restore USDA Forest Service resiliency to forest and range ecosystems, enabling them to cope with an uncertain is to restore resiliency future. Natural resource managers and policymakers are awash in information from to forest and range a growing body of science, with little time to sort through it, let alone assimilate the ecosystems, enabling many different sources and interpretations of the best available science. them to cope with an Regional research and management executives requested a review of the large uncertain future. body of scientific information on eastside moist mixed-conifer (MMC) forests within the context of the broader forest landscape in eastern Oregon and Wash- ington. This focus was motivated by a lack of up-to-date management guidelines, scientific synthesis, and consensus among stakeholders about management direction in the diverse MMC type. Understanding complex ecological and social processes and functions across landscapes requires an integrated assessment that combines multiple scientific disciplines across spatial and temporal scales. Accordingly, this synthesis compiles existing research, makes connections across disparate sources, and addresses multilayered natural resource issues. It has been prepared to assist land managers in updating existing management plans and on-the-ground projects that are intended to promote resilience in MMC forests and riparian areas. We consider management flexibility at the local scale critically important for contending with specific legacy effects of management and the substantial ecological variation in MMC forest conditions, as well as for adapting management to local social and policy concerns. Our hope is that this synthesis will serve as a reference that provides a con- densed and integrated understanding of the current state of knowledge regarding MMC forests, as well as an extensive list of published sources where readers can find further information. We also hope to enhance cross-disciplinary communica- tion and enrich dialogue among Forest Service researchers, managers, and external stakeholders as we address common restoration concerns and management chal- lenges for MMC forests in eastern Oregon and Washington. Key sections of this synthesis include: • A description of MMC forests and their context in the broader landscape of eastern Oregon and Washington. • Key concepts of restoration and the landscape perspective. • A comprehensive summary of pre-Euro-American settlement conditions in MMC forests. ii • A description of the socioeconomic context in the region. • A summary of human impacts on MMC forests. • Broad management implications of research findings. • A practical list of management considerations for diagnosing restoration needs and designing landscape approaches. Moist Mixed-Conifer Forests Mixed-conifer forests are a major component of the dry-to-wet conifer forest com- plex that is widely distributed across eastern Oregon and Washington. Among other factors, these forests are important for carbon sequestration, watershed protection, terrestrial and aquatic wildlife habitat, and outdoor recreation, and they provide economic opportunities through provisioning of a wide variety of forest products. MMC forests cover a large area east of the crest of the Cascade Range in Oregon and Washington, where grand fir, white fir, and Douglas-fir are the dominant late- successional tree species. MMC forests can be considered intermediate between drier conifer forests where pine was historically